The present invention relates to a driving wheel torque control device for a vehicle including slip control quantity setting means for setting a driving wheel torque reduction control quantity according to a slip condition of a driving wheel of the vehicle with respect to a driving direction.
Conventionally, such a control device is known from Japanese Patent Publication No. 52-198, for example.
In the conventional control device, a slip condition of the driving wheel is detected, and a driving torque of the driving wheel is reduced according to the slip condition detected so as to obtain a maximum driving force. A critical lateral force to be generated at the driving wheel increases with a reduction in driving force rather than the maximum driving force. Accordingly, when the vehicle is steered in detecting the slip condition and reducing the driving force, a yaw motion desired by an operator is generated, provided that a steering quantity is within a range not exceeding the critical lateral force. However, when the steering quantity is so large as to exceed the critical lateral force, the desired yaw motion is not generated. In this case, the yaw motion tends to become under-steering in a front-engine front-drive (FF) vehicle, while it tends to become over-steering in a front-engine rear-drive (FR) vehicle.